<!DOCTYPE HTML>
<html>
<head>
<meta charset="utf-8" />
<title>5-1什么是运算符</title>
</head>
<body>
    <div align="center">
        <?php
        $a = 1;
        $b = 1;
        echo $c = $a + $b;
        ?>
    </div>
</body>
</html>